In growing cities, open spaces are a rarity. This was also true of the site of the former slaughterhouse in Sankt Marx, Vienna. For about a decade, the approximately 25,000 square meter area next to the Tangente motorway remained unused – at least commercially. Several associations seized the opportunity to create space for themselves: for sports, gardening, parties, and skateboarding. Within a short time, a self-organized urban open space emerged, which was developed, used, and transformed by Vienna's skate, DIY, and neighborhood scenes for about ten years.

On a gravel surface, skate enthusiasts continuously built a concrete landscape of bowls and ramps starting in 2016 – complemented by graffiti, mosaics, raised beds, a shipping container, and improvised seating areas. The project was run by the collective ALM-DIY and was based on a temporary use agreement with Wiener Standortentwicklung GmbH (WSE), a subsidiary of Wien Holding.

In 2024, it was announced that the future Vienna Holding Arena would be built on the site; the contract with the clubs expired in December 2025, forcing the temporary use concepts to make way for construction equipment. However, a few people refused to vacate the space they had grown fond of, leading to a police intervention in April 2026.

"St. Marx for all" was emblazoned on one of the self-built sheds that were demolished. The skate park also had to make way. This marks the end of a roughly ten-year tradition whose significance extends far beyond skateboarding: St. Marx was simultaneously a meeting place, workshop, garden, concert venue, and street art area – and ultimately stood as a prime example of the question of who owns the city.

The area was one of the rare examples of an open "third place" in the heart of a major European city: an urban space of possibility where, instead of exploitation, artisanal improvisation, collective appropriation, and non-commercial use were paramount. The unconventionally designed concrete landscape arose from physical and material DIY knowledge, such as formwork, mixing ratios, and repair practices.

What was created on the site in Vienna's third district during this period was hardly documented in writing or pictures. Was the clearing and redevelopment of the site also meant the loss of the independent arts scene's work?

As part of the European campaign Twin it!,  a team from the University of Art and Design Linz documented the DIY skatepark in Sankt Marx as a digital cultural heritage asset. This resulted in a digital 3D model of the skatepark, which interested parties can now explore in the cultural database in a high-resolution, georeferenced format.

In this way, digitization preserves a vanished but for many significant place and inscribes it into the city's collective memory. "St. Marx for all" becomes discoverable as a new chapter in the city's history and protest history.

The digital overview model is based on several thousand high-resolution photos taken with a small drone weighing less than 250 grams. However, due to the dense vegetation, low-hanging branches, and numerous strings and cables strung across the area, a conventional drone flight was not possible. Therefore, the drone was mostly carried in the hand like a camera through the park. Photos were taken from this low perspective and subsequently processed using photogrammetry to create a three-dimensional model.

The result is a georeferenced 3D model of the entire area, which also allows for the simulation of bird's-eye views that were not possible during the physical recording. The digital model thus even enables new, previously unseen perspectives on the skate park.

The digital recording was also a form of participatory field research. The recordings were made during the skatepark's operation, in interaction with the DIY and skate scene. Renderings of the 3D model were subsequently presented not only in academic contexts but also circulated on social media within the scene, where they are now widely known. The model is therefore not a closed museum piece, but rather part of an ongoing collective process of memory.

The digital reconstruction itself was an experiment involving numerous DIY trials. Beyond handheld drone photogrammetry, other methods were tested and combined in unconventional ways, such as precise laser scans of selected obstacles using a mobile LiDAR scanner, and 3D Gaussian splatting, which allows the urban environment to be experienced as an immersive visual space. The data can be used to create 3D prints of characteristic elements, for example, at a scale of 1:8, playable with a finger skateboard. Each method has its own strengths, limitations, and artifacts. It is precisely this interplay that makes the models so fascinating as research objects.

Crucially, all models are made openly accessible and freely reusable under a free license. In this way, the project builds on the DIY logic of the skatepark and extends it into the digital realm: what was built collectively and improvisationally on-site should also remain openly processable as a dataset – by other researchers, by the skate scene itself, and by subsequent artistic projects. A kinship can thus be seen between the DIY community and open-source culture: shared tools, shared knowledge, and no ownership that restricts further use.

In this way, the digital representation enters into a tension with the physical loss: it doesn't replace the skatepark, but it preserves structures, surfaces, and inscriptions that would otherwise have disappeared with the bulldozer. The DIY skatepark Sankt Marx thus becomes a case study of how self-organized, subcultural urban spaces can be understood and treated as digital cultural heritage – especially when they no longer physically exist.